Cycloolefin-based polymer is a polymer obtained by polymerizing cycloolefin-based monomer such as norbonene and has advantages in high transparency, heat resistance, a resistance to chemicals, but low birefringence and low absorption, compared to conventional olefin polymer. In considering that the norbonene-based resin can be a candidate material of substrate for flexible display due to its excellent optical property, the polymer needs a good adhesion to metal besides the heat resistance. That is, the polymer should have excellent adhesion to silicon, aluminum, copper, gold, silver, titanium, nickel and the like. Thus, a polar functional group has to be introduced to the polymer to improve the adhesive property.
When the cycloolefin-based monomer includes a polar group such as an ester group, the polar group increases a charge between molecules and adhesiveness to metal or other polymer, thereby being applied usefully for electronic material. Thus, the polymerization or copolymerization of norbonene including as ester group has been focused steadily (U.S. Pat. No. 3,330,815, EP0445755A2, U.S. Pat. No. 5,705,503, U.S. Pat. No. 6,455,650).
The catalyst having a complex structure must be used at an excessive amount of the catalyst to monomer of 1/100 to /1400 in the polymerization of norbonene including as ester group. Nevertheless, the polymerization yield was low and here was a difficult problem to remove the remnant catalyst.
The present inventor found that the catalyst having high activity for polymerization of cycloolefin-based polymer could be obtained by activating divalent palladium compound or zeo-valent palladium compound to phosphonium compound such as [Cy3P—H]+[B(C6P5)4]− (KR10-0843613B). However, in case of some polar cycloolefins, the activity of catalyst is high at the low ratio of monomer/catalyst, but decreases sharply, if the ratio increased. This may be because that, as shown in reaction scheme 1, the propagation occurs when two metal centers acts simultaneously together. Namely, because the polar cycloolefin-based monomer has two ligands of an olefin group and a polar group to coordinate the metal, the propagation occurs by coordinating the olefin group with other metal after the polar group coordinates with on metal. If the polymerization proceeds according to the mechanism, polymerization rate is in inverse proportion to the square of the metal concentration. The activity of catalyst gets sensitive to the concentration of catalyst.

Therefore, there is still a need for the compound having high catalytic activity in polymerization even at high ratio of monomer/catalyst.